Conveyer screw



me@ 27 im@ l A, B, CARL-SON 49mm CONVEYER SCREW Filed April 14, 19117l Patented Dec. 27, 1949 This invention relates to improvementslh'cnveyor screws and more particularly to astiiial, non-flexible conveyor screw Suitablefr lilse, for example, for moving coal 'in` a fstoker.

EManufacturers of certain typs of fcoalsokr-s, and 'particularly those fwh'o "mainfactre vbinfe'e'd 'type stokers, vhave foun'dit i'mfracticalfto incorporate in their 'products coal conveyor screws of fsin'gle 'piece cofi'struction. The *exnses and diiiiculti'es encountered-in'-the'manib factlring, handling, installation, and servicing of the single piece units havef'made it'expedient to l use sectional Screws' in such applications.

Various schemes havebeen provided lfc'a'rapilying power to sectionalscre'ws -in lsuch strikers, ht'a c'oinnion diiculty hasheen-ekeriencediin a'llsdesigns. When the direction `off the travel ijf the-'coal is` away from the point'ofpowrabblica'- tion, the thrust 'reaction aganstfth'e 'inovnerft gether axially, but, thetorqe reactiontendsfto twistl s'ai'dsections 'and tov cause :asepar'atiowf the tends of fthe night on any' one lse'tiohffr'm th'ee'ids of the flights on the 'next 'adjacentse tions. ehehelotherfnand;whentneeireenn 'f the'travelof the coal'istoward'ithepont 'of poweiiplication, the torque lreactionfteiidsjto ""hld the, ends of the nights together when fthey *are ovrlanped, V4lout the thriist reaction :tends I"to senaratethe -section axially. {It-willthu's-beapg pa'ijeritthat an `adequate r'rrieans" fi co`1'1p'liii'g'- said sections one* to 4another --isl a necessity.

Scti'ralconveyor Y`screws Y"of prior "co`r'istru'c t A-a've-incorliiorated means A*for 'fastening-the sctiris thereof together, v'but in all f* designs 1*f which I am aware, said 1"fastening `-ineanshave iifnnededjniore `01"-le'ssftli-efree movement of the conveyed material pastthe joints L@between 'said s'c'tiris. `Examples "offsuc'h obstructioiisinay-'fbe td indesignsfor screws 'which have enlargeme'ntsin the 'core'shafts exposed'bolt or"sc'irevv headsor interruptiorisiin the screw flight Vat 4'said `ir'ts. lfA-ny obstructions of these or otherftyns tends t'ocause the-material lcein'grnoved to v` 11`21.'k,

tion, promotes excessive degradation or' grinding of said material, l'aiid `Vloften Itia-rises lndue wear onfthe screws, conveyor'tubs--andthe -driviig mechanisms.

inra' face whiehiiesl` entirelyewitnin finer-Gnner 55 2I of the shaft I8 and the end I3 of said shaft II y are brought together to an abutting position.

The night I8 terminates in a face parallel and identical to said face I5 and is positioned, with regard to the shaft end 2l, so that the two faces may abut perfectly when said ends I3 and 2| are brought together as in Fig. 1. A key-hole slot,

shown generally at 22, is provided in said flight I8 and in the face thereon corresponding in d1- mensions and position to those of the slot I6.

When the ends I3 and 2|, and the two faces, are brought together as above said, the two slots I6 and 22 are directly opposite each other and a key 23, having dimensions corresponding to the combined interior dimensions of the two slots, may be driven into said slots to rigidly secure the two screw sections each to the other. Said key may be formed of alloy steel or non-ferrous material of single piece or laminated construction,

and when of the latter design, the laminatons 24 of said key may be held together by rivets 25, as illustrated in the Fig. 2. The surfaces of the nights I2 and I9 about the round portions of the two slots may be slightly countersunk if desired, and said link may be lightly peaned adjacent to said countersunk surfaces, after assembly of the sections, to firmly hold the link in proper position.

It will readily be understood that, with the conveyor screw sections attached in the manner hereinbefore described, all of mating parts thereof are flush with eachother and that there are no projecting parts whatsoever which will tend to obstruct the passage of material over said sections or over the joints therebetween. When said material is moved by the screw toward the point at which power is applied to the latter, the torque supplied at said point will be transmitted from one section to another through the faces on the nights. the sections will prevent an axial separation thereof which would otherwise occur because of the thrust reaction against the movement of said material. Furthermore, when said screw is used to move material away from said point, of power application, the torque applied to said screw will be transmitted from one section to another by means of the link and, as hereinbefore explained, a thrust reaction tending to prevent an axial separation of the sections will be present. It will be seen, therefore, that the sectional screw of my invention may be used lto move material in either direction regardless of the point thereon at which power is applied.

It will also be understood that, while I have illustrated and described only a portion of two sections of my conveyor screw, said screw may comprise any number of identical sections. The core shaft and night of each of said sections mayhave one end thereof of a construction like that described above with regard to the shaft II and night I2, and the opposite end of each section may be constructed as is that of the partially illustrated section which, comprises the shaft I8 and the night I9.

During this operation, the link joining Since the corresponding ends of the various sections of said screws of like size and night design are of identical dimensions, said sections are interchangeable, and Worn sections may easily be replaced with other sections as desired. A screw section of such construction having a right-hand" flight thereon, however, cannot be jointed to one having a left-hand" night; and, of desired, the key-hole slots may be positioned during manufacturing so that sections of screws of different diameters cannot be fastened together, thus making it impossible for a repair man to accidentally replace a section with one of improper size or design.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom; but the appending claims should be construed as broadly as permissible in view of the prior art.

I claim:

l. A conveyor screw, comprising: a plurality of core shafts having abutting ends and a common axis; helical nights, one on each of said shafts; abutting faces on adjacent ends of said nights lying wholly within the contour of the latter; a slot in each of said abutting faces, one of said slots being opposite another; and, a link disposed entirely within said contour and adapted to be received by said opposing slots whereby said nights may be secured one to another without projections in said contour thereof, said abutting ends of the flights being nush without overlapping and the contour of the nights at the point of coupling being the same as elsewhere in their length to provide, in effect, a continuous night of uniform contour and strength for the full length of the screw.

2. A conveyor screw, comprising: a plurality of core shafts having abutting ends and a common axis; helical nights, one on each of said shafts; abutting faces normal to the plane of said nights and lying wholly within the contour of the latter; a slot in each of said abutting faces, one of said slots being opposite another; and, a link l disposed entirely within said contour and adapted to be received by said opposing slots whereby said nights may be secured one to another without projections in said contour thereof, said abutting ends of the nights being nush without overlapping and the contour of the nights at the point of coupling being the same as elsewhere in their length to provide, in effect, a continuous night of uniform contour and strength for the full length of the screw.

3. A conveyor screw, comprising: a plurality of core shafts having abutting ends and a common axis; helical nights, one on each of said shafts; abutting faces on adjacent ends of said nights lying wholly within the contour of the latter; a key-hole slot in each of said abutting faces, one of said slots being opposite another; and, a link disposed entirely within said contour and adapted to be received by said opposing slots whereby said nights may be secured one to another without projections in said contour thereof, said abutting ends of the nights being nush without overlapping and the contour of the nights at the point of coupling being the same as elsewhere in their length to provide, in effect, a continuous night of uniform contour and strength for the full length of the screw.

4. A conveyor screw, comprising: a plurality of core shafts having abutting ends and a common 75 axis; helical nights, one on each of said shafts;

abutting faces on adjacent ends of said flights lying wholly within the contour of the latter; a slot in each of said abutting faces, one of said slots being opposite another and all of said slots being uniformly positioned relative to said axis; and, a link disposed entirely within said contour and adapted to be received by said opposing slots whereby said ights may be interchangeably secured one to another without projections in said contour thereof, said abutting ends of the flights being flush without overlapping and the contour of the flights at the point of coupling being the same as elsewhere in their length to provide, in effect, a continuous flight of uniform contour and strength for the full length of the screw.

5. A conveyor screw, comprising: a plurality of core shafts having abutting ends and a common axis; helical flights, one on each of said shafts; abutting faces on adjacent ends of said flights lying wholly within the contour of the latter; a key-hole slot in each of said abutting faces, one of said slots being opposite another and all of said slots being uniformly positioned relative to said axis; and, a link disposed entirely within said contour and adapted to be received by said opposing slots whereby said flights may be interchangeably secured one to another without projections in said contour thereof, said abutting ends of the flights being flush without overlapping and the contour of the flights at the point of coupling being the same as elsewhere in their length to provide, in effect, a continuous flight of uniform contour and strength for the full length of the screw.

6. A conveyor screw, comprising: a plurality of core shafts having abutting ends and a common axis; a projection on an end of one of said shafts and a recess in an end of another of said shafts adapted to receive said projection; helical ights, one on each of said shafts; abutting faces on adjacent ends of said flights lying wholly within the contour of the latter; a slot in each of said abutting faces, one of said slots being opposite another; and, a link disposed entirely within said contour and adapted to be received by said opposing slots whereby said flights may be secured one to another without projections in said contour thereof, said abutting ends of the flights being flush without overlapping and the contour of the flights at the point of coupling being the same as elsewhere in their length to provide, in effect, a continuous flight of uniform contour and strength for the full length of the screw.

7. A conveyor screw, comprising: a plurality of core shafts having abutting ends and a common axis; a projection on an end of one of said shafts and a recess in an end of another of said shafts adapted to receive said projection; helical flights, one on each of said shafts; abutting faces normal to the plane of said flights and lying wholly within the contour of the latter; a key-hole slot in each of said faces, one of said slots being opposite another and all of said slots being uniformly positioned relative to said axis; and, a link disposed entirely within said contour and adapted to be received by said opposing slots whereby said flights may be interchangeably secured one to another without projections in said contour thereof, said abutting ends of the flights being flush without overlapping and the contour of the flights at the point of coupling being the same as elsewhere in their length to provide, in effect, a continuous flight of uniform contour and strength for the full length of the screw.

ARTHUR B. CARLSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 793,958 Richardson July 4, 1905 2,118,289 Birkenbeuel May 24, 1938 2,142,896 Harman Jan. 3, 1939 2,308,075 Hahn Jan. l2, 1943 

